import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class Test {
    class Solution {
        public List<Integer> findSubstring(String s, String[] words) {
            List<Integer> ret = new ArrayList<>();
            Map<String, Integer> hash1 = new HashMap<>();
            for(String  str :  words) {
                hash1.put(str,hash1.getOrDefault(str,0)+1);
            }

            int len = words[0].length();
            int m = words.length;
            for(int i = 0;i < len;i ++) {
                Map<String, Integer> hash2 = new HashMap<>();
                for(int left = i,right = i,count = 0;right + len <= s.length();right += len) {
                    //进窗口
                    String in = s.substring(right,right + len);
                    hash2.put(in,hash2.getOrDefault(in,0) +1);

                    //判断
                    if(hash2.get(in) <= hash1.getOrDefault(in,0)) {
                        count ++;
                    }
                    if(right-left+1 > len*m) {
                        //出窗口
                        String out = s.substring(left,left+len);
                        if(hash2.get(out) <= hash1.getOrDefault(out,0)) {
                            count --;
                        }
                        hash2.put(out,hash2.get(out) - 1);
                        left += len;

                    }
                    if(count == m) {
                        ret.add(left);
                    }
                }

            }
            return ret;
        }
    }
}
